Simple and basic Android TTS all ready to be turned into a unity plugin

TTSActivity.java

package uk.co.dyadica.ttsbasic;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.speech.RecognizerIntent;
import android.speech.tts.TextToSpeech;
import android.speech.tts.UtteranceProgressListener;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.Locale;

public class TTSActivity extends AppCompatActivity
{
    public TextToSpeech talker;

    public static Locale vocLocale = Locale.UK;
    public static float vocPitch = 1f;
    public static float vocRate = 1f;

    int MY_DATA_CHECK_CODE = 10;

    Button b1;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_tts);

        CheckAndGo();

        b1 = (Button)findViewById(R.id.button);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SpeakText("Hello");
            }
        });
    }

    @Override
    protected void onDestroy()
    {
        if(talker != null)
        {
            talker.stop();
            talker.shutdown();
        }

        super.onDestroy();
    }

    @Override
    protected void onPause()
    {
        if(talker != null)
        {
            talker.stop();
        }

        super.onPause();
    }

    @Override
    protected void onResume()
    {
        if(talker == null)
        {
            InitialiseSpeaker();
        }

        super.onResume();
    }

    public void CheckAndGo()
    {
        Intent checkIntent = new Intent();
        checkIntent.setAction(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);
        startActivityForResult(checkIntent, MY_DATA_CHECK_CODE);
    }

    public void InitialiseSpeaker()
    {
        talker = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener()
        {
            @Override
            public void onInit(int status)
            {
                if(status != TextToSpeech.ERROR)
                {
                    talker.setLanguage(vocLocale);
                    talker.setPitch(vocPitch);
                    talker.setSpeechRate(vocRate);
                }
            }
        });
    }

    public boolean isSpeaking()
    {
        return talker.isSpeaking();
    }

    public void SpeakText(String toSpeak)
    {
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP)
        {
            talker.speak(toSpeak, TextToSpeech.QUEUE_FLUSH, null, null);
        }
        else
        {
            talker.speak(toSpeak, TextToSpeech.QUEUE_FLUSH, null);
        }
    }

    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        if (requestCode == MY_DATA_CHECK_CODE)
        {
            if (resultCode == TextToSpeech.Engine.CHECK_VOICE_DATA_PASS)
            {
                // success, create the TTS instance

                InitialiseSpeaker();
            }
            else
            {
                // missing data, install it
                Intent installIntent = new Intent();
                installIntent.setAction(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
                startActivity(installIntent);
            }
        }
    }
}